Publications by authors named "Marjorie Matocq"
Range expansion and contraction are among the most common biotic responses to changing environmental conditions, yet much is to be learned about the mechanisms that underlie range-edge population dynamics, especially when those areas are points of secondary contact between closely related species. Here, we present field-measured parentage data that document the reproductive outcomes of changes in mate availability at a secondary contact zone between two species of woodrat in the genus Neotoma. Changes in mate availability resulted from drought-driven differential survival between the species and their hybrids.
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- Rodent middens are piles of animal poop that can show us what plants and animals lived in an area a long time ago.
- In the Americas, scientists study these middens to understand how species changed with the environment and other historical factors.
- To get the most out of these studies and help with conservation efforts, researchers need to work together and explore more midden records from around the world.
Rabbit hemorrhagic disease virus 2 (RHDV2 or Lagovirus GI.2) began circulating in wild lagomorph populations in the US in March 2020. To date, RHDV2 has been confirmed in several species of cottontail rabbits (Sylvilagus spp.
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- Hybridization significantly impacts the evolution of multicellular eukaryotes, but the influence of ecological factors on this process is not well understood.
- A 3-year study of hybridization between Bryant's woodrat and desert woodrat in Whitewater, CA, revealed that about 40% of individuals have mixed ancestry due to backcrossing.
- Interestingly, the survival rates of hybrids were similar to the more abundant parental species, while the less common parental species had lower survival rates, suggesting hybridization is limited by the abundance of desert woodrat rather than by negative selection against the hybrids.
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- The microbiome significantly influences an organism's traits and is shaped by ecological and evolutionary factors.
- In a study of a hybrid mammal species, researchers found that while the host's genetic background primarily determines gut microbiome composition, habitat affects dietary choices, which in turn influences microbial diversity.
- Increased dietary diversity is linked to greater stability in gut microbiomes, especially in the more adaptable species, suggesting that host ancestry and diet collaboratively impact microbiome characteristics and the overall adaptability of the organism.
The woodrats or packrats of the genus have been the subject of a wide array of research including paleoecology, physiology, morphological evolution, systematics, speciation, and hybridization. In recent years, much work has been done to elucidate evolutionary relationships within and between closely related species of the genus; in particular the addition of newly collected specimens from critical geographic regions has provided new opportunities for taxonomic assessment. Given these new data and their potential, parsimony (PARS), maximum likelihood (ML), and Bayesian inference (BI) analyses were conducted on DNA sequences obtained from nine individual genes (four mitochondrial loci: , , , and ; five nuclear loci: , , , , and ) to estimate the phylogenetic relationships among 23 species of .
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- A study assessed the tolerance of two herbivorous woodrat species (desert woodrat and Bryant's woodrat) to creosote bush, a toxic plant, across a 900 km area in the US southwest.
- Researchers used plant metabarcoding of feces to determine consumption levels and conducted feeding trials to measure tolerance, finding significant differences between the species.
- Woodrats living close to creosote bush were more tolerant to its toxic resin, suggesting that herbivores can adapt to toxic plant metabolites even when not directly exposed, prompting further investigation into genetic factors behind this tolerance.
The genomic architecture underlying the origins and maintenance of biodiversity is an increasingly accessible feature of species, due in large part to third-generation sequencing and novel analytical toolsets. Applying these techniques to woodrats (Neotoma spp.) provides a unique opportunity to study how herbivores respond to environmental change.
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- Conservation genetics has evolved significantly in the last 50 years, offering valuable tools for managing species, particularly through the use of pedigrees to assess and enhance genetic diversity in threatened populations.
- High throughput sequencing technologies have raised questions about the necessity of continuing pedigree collection, as they can provide insights into relatedness and inbreeding.
- The authors argue that pedigrees remain essential and, when integrated with genomic data, enhance conservation efforts by addressing data issues while fostering collaboration among researchers and communities.
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- The study investigates how genomes of two distinct species of woodrats, the desert woodrat and Bryant's woodrat, interact at a hybrid zone in Southern California after developing separately (allopatric divergence).
- Researchers collected genetic data from 353 individuals to analyze patterns of ancestry and introgression (gene flow between species), finding that hybrids were rare and mostly consisted of a few first-generation hybrids and many backcrosses.
- The findings revealed that while many genomic regions showed introgression, this did not correlate with levels of divergence, suggesting that factors like genetic drift may play a significant role in shaping genetic interactions at the hybrid zone rather than just adaptation to different diets.
Local adaptation can occur when spatially separated populations are subjected to contrasting environmental conditions. Historically, understanding the genetic basis of adaptation has been difficult, but increased availability of genome-wide markers facilitates studies of local adaptation in non-model organisms of conservation concern. The pygmy rabbit (Brachylagus idahoensis) is an imperiled lagomorph that relies on sagebrush for forage and cover.
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- Ecotones, where different biotic communities meet, serve as valuable settings for studying how environmental factors impact the diet and evolution of herbivores, such as woodrats.
- The study analyzed the diets of two woodrat species across an ecotone and found they have distinct dietary preferences despite hybridization, with one species having a more diverse diet.
- The research reveals that the woodrats adapt their feeding strategies based on local plant availability, aiming to maximize nutrition while avoiding potentially toxic plants.
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- The montane sky islands of the Great Basin, like the Pine Forest Range in Nevada, host distinct habitats that are at risk due to environmental changes, specifically for the Humboldt yellow pine chipmunk.
- Researchers compared genetic diversity between chipmunks in this isolated region and those from more connected populations, finding that the Humboldt chipmunks have lower genetic variation even as some show strong ties to chipmunk populations in other mountainous areas.
- Pathogen screening indicated that the Humboldt chipmunks had higher pathogen loads compared to the least chipmunks in the same area, underscoring the importance of conservation efforts to protect these isolated species and their unique ecosystems.
Understanding how species have responded to past climate change may help refine projections of how species and biotic communities will respond to future change. Here, we integrate estimates of genome-wide genetic variation with demographic and niche modeling to investigate the historical biogeography of an important ecological engineer: the dusky-footed woodrat, Neotoma fuscipes. We use RADseq to generate a genome-wide dataset for 71 individuals from across the geographic distribution of the species in California.
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- Conservation biologists have begun utilizing translocations, which involve moving species to new locations, to help recover declining populations and reintroduce species that have disappeared from certain areas.
- In Nevada, translocation efforts since 1968 have successfully helped restore desert bighorn sheep populations, but most of these efforts occurred before genetic tools were used to inform management decisions.
- Research on genetic diversity and structure among desert bighorn sheep herds showed distinct genetic patterns, indicating that translocated populations often reflect the diverse genetic backgrounds of the original source herds, highlighting the importance of genetics in conservation practices.
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- Climate change is affecting the range limits of hybridizing species, but understanding this relationship is complicated, often due to insufficient data linking fitness to climate and hybrid zone movement.
- A study of two woodrat species in California reveals that smaller-bodied woodrats benefit from better survival rates during specific weather conditions, which influences the dynamics of their hybrid zone.
- The hybrid zone between the two species shifted northward by about 150 meters over six years, demonstrating how climate and competition interact to drive species distribution changes.
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- Topographically complex regions, both terrestrial and marine, are hotspots for biodiversity influenced by geological factors and evolutionary processes over time.
- These regions experience fluctuations in topographic diversity that correlate with tectonic and climatic changes, affecting species formation through mechanisms like vicariance and dispersal.
- Integrating biological and geological studies is essential for exploring different models of species diversification and advancing biogeographical research.
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- The text discusses how groups of organisms, such as different species or populations, can vary in non-exclusive ways, including their physical traits (phenotypic), genetic makeup, and evolutionary responses.
- It focuses on a study involving two species of woodrats, revealing that even though they are distinct in both physical and genetic aspects, they are evolving along a similar evolutionary path.
- This finding is significant because it suggests that since these species are in contact with each other, their similar evolutionary responses may limit the forces that typically help reinforce their species boundaries.
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- Conservation planning needs to consider landscape connectivity at different scales, from individual animal ranges to large regions, especially in light of land use changes and climate impacts.
- The study presents a multiscale connectivity framework that combines various methods to prioritize habitat conservation for the threatened Mohave ground squirrel, factoring in the placement of renewable energy projects.
- By analyzing habitat connectivity changes based on land and climate scenarios, the approach identifies key areas for conservation, aiming to protect both essential habitats and movement corridors for various species.
Dusky-footed woodrats are territorial cricetid rodents that individually occupy large stick houses from which they foray to gather food, find mates, and engage in other activities. These rodents are often bitten by Ixodes spp. ticks and are reservoirs of some strains of tick-borne bacterial pathogens such as Anaplasma phagocytophilum and Borrelia burgdorferi.
View Article and Find Full Text PDFPatterns of host-parasite association may vary across the landscape in part because of host and parasite diversity, divergence, local ecology, or interactions among these factors. In central coastal California, we quantified parasite prevalence, infection intensity, and diversity in two sister species of woodrats (Neotoma fuscipes and Neotoma macrotis) where the species co-occur (sympatry) and where each species exists alone (allopatry). In feces from 50 adults we identified seven taxa: the protozoans Eimeria, Giardia, and Cryptosporidium, the nematodes Trichuris, Aspicularis, and Eucoleus, and a cestode in the family Anoplocephalidae.
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- The degree of interbreeding between two woodrat species, Neotoma bryanti and N. lepida, is influenced by ecological, behavioral, and genetic factors, particularly at their habitat boundaries.
- A study found that 13% of individuals showed hybrid traits, but hybrids and parental populations were distinctly separated by habitat type.
- Adult hybrids had similar survival rates as purebred individuals, but juvenile hybrids had lower chances of reaching adulthood, indicating that reproductive isolation is enhanced by habitat selection and survival differences among offspring.
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- Female mate preferences were studied in Desert and Bryant's Woodrat in a contact zone to understand how selection affects choice and hybridization risks.
- Results showed that N. lepida females preferred their own species, while N. bryanti females displayed no clear preference. Sympatric females (from overlapping populations) were less likely to mate and exhibited more aggression than allopatric females (from separate populations).
- The study concluded that body size and aggression heavily influenced mate choice, with the smaller N. lepida being more selective and the larger N. bryanti being more accepting of different species.
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- - The study focuses on understanding genetic diversity and connectivity in an endangered woodrat subspecies amidst the altered landscapes of California's Great Central Valley, where remnant populations have faced significant demographic changes and extinctions.
- - Using 14 microsatellite loci and genetic data from both mitochondrial and nuclear sources, the researchers aim to reconstruct historical patterns of diversity and connectivity while assessing past habitat availability to establish possible scenarios affecting current genetic variation.
- - Results indicate that the Central Valley populations possess unique genetic traits from hybridization with other woodrat species, and highlight challenges in analyzing population histories, especially when severe bottlenecks occur after hybridization.